Is There Something In The Air?

What EH&S Managers Need to Know About Vapor Intrusion

By

Khaled Chekiri, Ph.D., P.E. and Jeffrey A. Bolin, M.S., CHMM

Dragun Corporation - April 18, 2011

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What is VI?

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Why Should You Care?

Regulatory concerns

Property transaction concerns

Legal liability

Health concerns

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VI – Federal Regulatory Timeline

USEPA VI Path

November 2002: EPA Draft VI Guidance (not applicable to petroleum)

March 2011: EPA solicited (more) comments

September 2011: Petroleum guidance

February 2012: Technical updates

November 2012: Final VI Guidance (expected)Dragun Corporation

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VI – State Regulatory Arena

2004 – 7 States (Including Michigan)

2010 – 32 States

2012 – 32 +

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Regulatory Concerns

Re-openers?

What do you mean it’s not closed?

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Where Do I Need to be Concerned?

Anywhere there is “potential” from a previous

release.

Notable VI sites include

Love Canal in Niagara Falls, NY - 70's

Hillside school in Needham, MA - 80's

Redfield site in Denver, CO. - 90's

Bishop St. site in Cambridge, ON. - 00's Dragun Corporation

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Property Transaction Concerns

Buying/Selling Property

Merger/Acquisition

Confusion = Delays = $$$

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Property Transaction Concerns

All Appropriate Inquiries (AAI) ASTM 1527-05

Vapor Encroachment Condition (VEC) ASTM 2600-10

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Property Transaction Concerns

Where is your site relative to a known plume?

…or just within an AOC?

Non-petroleum hydrocarbon 1/3 mile (1,760 feet)

Petroleum hydrocarbon 1/10 mile (528 feet)

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Property Transaction Concerns

AAI Continuing Obligations

Michigan Due Care

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Health Concerns

Employee Exposure?

What is an “okay” exposure?

ACGIH, PEL,

Something Else?

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Understand How VI Occurs?

Diffusion ~ slow vs. advection

Fick’s Law: Movement of molecules from a high concentration to a low concentration

Mass Movement (Flux) = D dC/dxDragun Corporation

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Attenuation Factor, α

Cindoor air

Csoil vaporα =

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Strategic Considerations

Safety

Economics

Social

Time constraints

Defensible results

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Designing a Proper Investigation

Critical thinking

Conceptual site model

Multiple lines of evidence

Other considerations

Sampling methods

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Critical Thinking

Does it make sense?

Data validation

Screening levels

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Conceptual Site Model

Geology

Water table

Contaminant

Underground utilities

Sensitive receptors

Existing and potential future buildings Dragun Corporation

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Multiple Lines of Evidence

Indoor air   Soil vapor (deep and shallow) Groundwater Background concentrations (ambient air) Building construction Soil stratigraphy Chemicals (presence, ratios) Temporal patterns (heating and cooling)

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Other Considerations

Access agreements

Regulator involved?

Risk communication

Potential litigation

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Indoor Air Sampling

Background sources

Sample custody

Temporal variability

Multiple home visits

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Soil Vapor Sampling

Passive Active

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Active Soil Vapor Sampling

Sub-slab probes Soil vapor points Dragun Corporation

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Sub-slab Sampling

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Sub-slab sampling - Duplicate setup

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Addressing VI?

Source remediation

Mitigation

Institutional controls

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Mini-Cases

Sebawaing, MI

Port Huron, MI

Salina, KS

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Salina, KS

Soil Vapor Points

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Take Home Messages

Properly assessing VI is complicated; it requires well thought-out strategy and execution – as with all data GIGO.

VI may or may not be part of environmental due diligence or other environmental assessments – it should be on your checklist to ask if it has been evaluated.

Don’t rush to remediate or mitigate based on VI data; do the data make sense?

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Questions?

Contact Information:

Khaled Chekiri, Ph.D., PE (kchekiri@dragun.com)

Jeffrey A. Bolin, M.S., CHMM (jbolin@dragun.com)

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